1. Field of the Invention
The present invention relates to a centrifugal force based platform, a microfluidic system including the same, and a method of determining a home position of the platform.
2. Description of the Related Art
Generally, a microfluidic device has a structure including a chamber storing a minute amount of fluid, a channel through which the fluid flows, a valve for controlling flow of the fluid, and various functional units receiving the fluid to perform predetermined functions thereon. A biochip has such a microfluidic structure arranged on a chip-type substrate, and is used to analyse the performance of various assays including biological reactions. In particular, a device that is designed to perform multiple step processes and manipulations using a single chip is referred to as a lab-on-a chip (LOC).
A driving pressure is generally required to transfer the fluid within the microfluidic device, and thus, capillary pressure or a pressure generated by a specifically prepared pump is used as the driving pressure. A lab compact disk (CD) or a lab-on a disk is a recently suggested platform that is shaped as a compact disk and transfer fluid by using centrifugal force.
Such centrifugal force based platforms perform various reactions on a sample, in particular a biological sample, such as immune serum tests and gene tests, in the chambers of the platforms, according to their use. The results of the sample reactions are detected using appropriate reaction detectors. In order to perform the sample reactions in the platforms and detect the results of the sample reaction by using the reaction detectors, it is necessary that the positions of valves, functional units, and chambers for detecting the reaction, which are disposed on a disk-type platform, be correctly determined. A spot of the platform, which is a base position for determining the positions of the valves, the functional units and the chambers, is referred to as a home, and a mark indicating the home is referred to as a home mark. A conventional method of determining the home position of a centrifugal force based platform is classified into a method of detecting light reflected by a mirror, a method of detecting a position at which transmission of light is shut down, or the like. However, such conventional method has insufficient reliability in determining a home due to errors generated when a platform is assembled or a home mark is formed.